On Sat, 26 Oct 1996, Darin Wayrynen wrote:
|} Which begs a question: why use a Giga-switch at all? |} |} With the head of line blocking feature/problem and scalability only to |} full duplex 100 mbps is a Gigaswitch something that should be used in a |} next generation NAP?
Nathan mentioned that MFS has started their new MAEs with a Catalyst or shared FDDI ring. Perhaps that has something to do with inital demand. An example of this is MAE-Houston or MAE-LA, neither of which presently require the bandwidth a Gigaswitch delivers. MFS has been sticking to the plan of adding hardware and/or capacity based on demand and traffic stats.
I really need to start reading responses to posts before posting myself. :-)
I think the Atlanta NAP, while probably a good idea, won't run into the head of line blocking problem in the extremely near future. Looking at the growth pattern of other exchange points leads me to believe this.
That may or may not be true. It's my opinion that an Atlanta based NAP makes much more sense than the existing MAE-LA nap. There isn't a major public NAP in the southeastern part of the United States, and it's quite possible that if done properly, all of the Major NSPs will want to go there for a common place to peer (even taking into account their propensity to move towards private peering). If they go there, I know we will. If you add in the typical 6 month bandwidth doubling trend it leads directly to my second opinion that it's not going to be enough bandwidth next year. The trend is real. If you are using up a FDDI link today, chances are you will be using 4 of them a year from now. Given the above, the amount of traffic could approach 100 Mbps on an outbound link quite rapidly, even for the small, mid size NSPs.
|} I'm not suggesting it's intended to be the next generation NAP, but |} you'd think that they would want to use the latest switches and |} technology available, rather than continue down the FDDI road.
What else would you suggest? Gigabit Ethernet hasn't been standardized yet, Cisco doesn't make a HIPPI interface, and some people prefer to not use ATM. FDDI has proven to very reliable, etc. Having ISPs continue to grow egress bandwidth has shown to be a bigger problem than the switch fabric at the larger exchange points.
Sticking my neck out, I would suggest ATM. It scales better today. Rather than the current trend of running multiple FDDI links to a switch to handle that egress (and ingress) bandwidth, you can use a single 0C3/OC12 link and leave the load balancing across multiple links problems behind. As for reliability, AADS has shown that you can build an ATM based NAP that is reliable. Yes there was a failure the other day, but there have been failures at the FDDI naps also. Darin -- \//// ( o o ) ====================================oOO-(.)-OOo========================== Darin Wayrynen, VP of Technology, (602) 303-9500 ext 3234, darin@good.net